The American Cancer Society notes that there are many reasons to quit smoking. For example,
The study, conducted by the National Cancer Institute and published in the JAMA Network Open, spanned approximately 19 years. It included 159,937 ex-smokers with an average age of 62.6 years.
Experts compared the eating habits of these people withHealthy eating index 2015. Those who scored the highest on this criterion had a 27% lower risk of death than those who scored the lowest.

In other words, ex-smokers who eat healthy can live longer than other people who quit smoking.
Also, participants with the highest scores were 24% less likely to die from cancer, 28% less – from heart disease, 30% less – from respiratory diseases.
As far as a healthy diet is concerned,The 2015-2020 Diet Guide for Americans says it includes adequate amounts of fruits, vegetables, leafy greens, beans, whole grains, dairy, seafood, total protein, vegetable protein, fatty acid foods. You also need to limit the amount of sodium consumed, refined grains, added sugars, saturated fats.
Smokers may need certain substances. These are vitamin C, E, some B vitamins, selenium, zinc, beta-carotene.
News stories cannot be equated with a doctor's prescription. Before making a decision, consult a specialist.